Don't modify request URL values from Caddyfile (fixes #1528)

HTTP redirects can use host-relative URLs. See discussion in #1497.

caddyhttp/httpserver/server.go

@@ -9,7 +9,6 @@ import (
 	"log"
 	"net"
 	"net/http"
-	"net/url"
 	"os"
 	"runtime"
 	"strings"
@@ -350,14 +349,6 @@ func (s *Server) serveHTTP(w http.ResponseWriter, r *http.Request) (int, error)
 		}
 	}
 
-	// URL fields other than Path and RawQuery will be empty for most server
-	// requests. Hence, the request URL is updated with the scheme and host
-	// from the virtual host's site address.
-	if vhostURL, err := url.Parse(vhost.Addr.String()); err == nil {
-		r.URL.Scheme = vhostURL.Scheme
-		r.URL.Host = vhostURL.Host
-	}
-
 	// Apply the path-based request body size limit
 	// The error returned by MaxBytesReader is meant to be handled
 	// by whichever middleware/plugin that receives it when calling